This invention relates to a lifting apparatus for removing a part, such as a tire vulcanizer bladder in a centered position, to avoid damage to adjacent parts and seals in a tire vulcanizer during the bladder removal process.
A bladder removal mechanism in which a center post is required to center the bladder is shown in U.S. Pat. No. 5,522,716. This mechanism is not adaptable to tire vulcanizers which do not have center posts of that type.
Also, in U.S. Pat. No. 5,360,327 a bladder replacing apparatus is provided which is mounted on the loader of the tire vulcanizing press. Since the loader is centered, the loading and unloading of the bladder is automatically in a centered position. This apparatus is not moveable from one tire vulcanizer to another because it is attached to the loader of the vulcanizer.
Bladders have also been removed and installed with a jib crane mounted on a forklift truck. It has been difficult to position the end of the jib crane over the bladder with this apparatus and as a result bladders have been pulled off at an angle, which has damaged the seals in the tire vulcanizer. Also, the molds and vulcanizer have been damaged. Two men have been needed to operate the forklift truck and jib crane, which has increased the cost of this operation.
The present invention is directed to a bladder loading and unloading apparatus for a tire vulcanizer wherein one operation can handle and center so that the bladders can be removed without damaging the vulcanizer molds and seals. A forklift truck may be used to lift the apparatus into a position adjacent the molds of the open vulcanizer. A separate boom for each bladder is connected to a respective bladder by a chain and the boom is raised extending the chain. Because of the flexibility of the apparatus of this invention the end of the boom may be moved to a centered position and then the boom may be raised to lift the bladder. The bladder is pulled out of the vulcanizer in a centered position and the seals are not damaged. This result is achieved without requiring the positioning of the apparatus in a precise relationship with the tire vulcanizer and therefore not only avoids damage to the tire vulcanizer and the seals, but the time required for the bladder servicing is reduced.
In accordance with one aspect of the invention there is provided a method of removing a tire forming bladder from a tire vulcanizer with a bladder removing apparatus, having a bladder lifting boom mounted on a horizontally movable platform, and an elongated flexible connecting member having a boom connecting end connected to the boom and a bladder connecting end comprising:
(a) fastening the bladder connecting end of the flexible connecting member to the bladder;
(b) raising the boom and placing the connecting member in tension for pulling the horizontally movable platform towards the bladder to a centered position wherein the boom connecting end of the flexible connecting member is positioned substantially directly over the bladder connecting end; and,
(c) continuing to raise the boom to lift the bladder in a centered position and remove the bladder from the tire vulcanizer in a vertical direction.
In accordance with another aspect of the invention there is provided a bladder lifting apparatus for lifting a tire forming bladder in an operating position to a detached lifted position directly over the operating position characterized by:
(a) a supporting frame movable into a position adjacent the operating position;
(b) a movable platform slidably mounted on the frame for sliding movement toward and away from the operating position;
(c) a lifting boom having an inner end mounted on the platform and outer end extending to a position over the bladder;
(d) a flexible connecting member extending from the outer end of the lifting boom to the bladder body;
(e) means to connect the flexible connecting member to the bladder, and;
(f) means to lift the lifting boom to put the connecting member in tension whereby, the movable platform is moved toward the operating position of the bladder and the boom is rotated into position with the outer end extending toward the centered operating position so that the bladder may be raised to the detached position directly over the operating position without any sidewise movement.
FIG. 1 is a view in perspective of the general assembly in position for removing a bladder with parts being broken away.
FIG. 2 is a plan view of the apparatus shown in FIG. 1 with parts broken away to show the post and sleeve construction.
FIG. 3 is sectional view taken along the plane of line 3xe2x80x943 in FIG. 2 with a sectional view of the bladder shown mounted in the tire vulcanizer.
FIG. 4 is a sectional view taken along the plane of line 4xe2x80x944 in FIG. 2.